The present disclosure relates to a toner case storing a toner (developer) used in a dry electro photographic print method and an image forming apparatus to which the toner case is attached.
Generally, a toner case (e.g. a toner cartridge) storing a toner used in a dry electro photographic print method includes a main body and a cover. The main body is formed in a box-liked shape, has an opening at an upper side and stores the toner inside. The cover is attached to the upper side of the main body to close the opening. In the main body or cover, a toner discharge port is formed so as to discharge the toner stored in the main body to a development device of the image forming apparatus. In the toner case, a toner agitating mechanism is provided so as to agitate the toner stored in the main body and to send the toner to a side of the toner discharge port.
The toner agitating mechanism includes, for example, a rotating member and an agitating member. The rotating member is, for example, a bar-formed member extending in left and right directions in the main body and has both ends rotatably supported in the main body. The agitating member is, for example, a board-formed member and has a base end side connected with the rotating member in the main body. When the agitating member rotates accompanying to rotation of the rotating member, the toner stored in the main body is agitated by a top end side of the agitating member.
When the agitating member rotates, the top end of the agitating member is moved while keeping in contact with a given area in an internal face of the main body and an internal face of the cover. Hereinafter, the above-mentioned given area is called as an “internal contact face”. Because the agitating member is made of a flexible material, when the agitating member rotates, the agitating member is elastically deformed between the rotating member and the internal contact face. Therefore, the top end of the agitating member is moved in a state keeping in contact with the internal contact face by suitable pressing force. Thereby, the toner stored in the main body is sufficiently agitated.
An outside shell of the toner case is formed by combining the separately molded main body and cover with each other. Therefore, a gap or a level difference may be formed in the boundary between the main body and cover Due to the structure of the toner case, the boundary between the main body and cover is exposed to an inside of the toner case and may be located in the internal contact face. Thus, in a case where the boundary between the main body and cover is located in the internal contact face, there is a problem that a noise called as a crack or a flick occurs when the agitating member rotates.
Cause of such a noise is mentioned below. That is, the top end of the agitating member is moved in the state keeping in contact with the internal contact face as mentioned above. While the top end of the agitating member is moved in the boundary between the main body and cover, because the top end of the agitating member runs over a gap or a level difference formed in the boundary, the top end is separated from the internal contact face for a moment and comes into contact with it again. Then, the top end of the agitating member strongly hits the boundary by the elastic force of the agitating member, thereby causing the noise.
Moreover, in the case where the boundary between the main body and cover is located in the internal contact face as mentioned above, there is another problem that it is feared that the agitating member is damaged by inserting the top end of the agitating member in the gap or level difference formed in the boundary when the agitating member rotates. Particularly, when the agitating member rotates in a reverse direction of a usual rotating direction, the agitating member may deeply insert in the gap or level difference in the boundary. In such a case, a danger of breaking the agitating member increases. The reverse rotation of the agitating member may be caused, for example, in the following case. That is, at an outer face side of the toner case, a rotation transmitting member is exposed, which transmits a rotating power from the image forming apparatus to the rotating member of the toner case when the toner case is attached to the image forming apparatus. When the toner case is attached to or detached from the image forming apparatus, the rotation transmitting member may hit any object so that the rotating member rotates in the reverse direction.